In this video, Leslie explains all about lateral inhibition using two rectangles. Watch to learn how this process helps us see edges of objects more clearly. Enjoy!
Transcript of Today’s Episode
Welcome to another episode of Interactive Biology TV, where we’re making biology fun! My name is Leslie Samuel. In this episode, Episode 34, I’m going to talk about how lateral inhibition enhances visual edges. What am I talking about? Well, you’re going to see right now.
Here, we have 2 rectangles. One is darker and the other is lighter. It’s just a solid gray color over here, and a solid darker gray, almost black color, over here. What I’m going to do is I’m going to show you something that’s quite fascinating, at least it’s fascinating to me. It illustrates how visual processing can lead to some interesting things. To a certain extent, it shows that what you see is not always what’s there.
What am I talking about? Well, what I’m going to do is I’m going to take this gray rectangle over here and I’m basically going to move it towards the other one. We’re going to see what happens. Remember it’s a solid gray color, the same color that I have over here, it’s the same color that I have over here, and throughout the entire rectangle. Now let’s put them together and see if anything happens. So I’m just going to move the one on the right towards the one at the left. And now, hopefully you can see this, depending on the monitor that you’re using, you may or may not be able to see this, but I’m guessing you will be able to see it.
What you’re going to notice here is right here at the border, you’re going to see that here is just a little lighter than over here. So before, it looked like a solid gray object, and I really hope you see this, or else this is pointless, and over here now, we’re seeing that it’s darker here than it is over here. If you don’t see it, look closely at the monitor and see if you see a little bit of a lighter edge here.
Now, is that lighter edge there? No, it really isn’t. But there’s something that’s happening inside your eye that’s making it seem as if it’s lighter over here and a little darker over here, you might be able to see that also. So, lighter on this side, and darker on this side, just a little bit. What we’re going to do is look at why that’s the case.
The main idea, though, is that the brain is set up to enhance visual edges so that you can see the edges more clearly. I find this to be very fascinating because to me, it illustrates that maybe what we see might not actually be what is there. And I don’t know how much that extends into everyday life, but it’s an interesting concept nonetheless. Now, let’s look at the cells that we have in the retina.
We looked at this already. We said that here we have the rods and this would be a cone, we said that here we have a horizontal cell, and here we have ganglion cells, and we also have amacrine cells. This is just a review of an earlier episode. The cell that I’m most concerned with now in terms of this process is the horizontal cell. You can see here, we have a number of rods, and we have a cone, and this horizontal cell goes laterally, and it connects to multiple rods and even connects to some of the cones. This is where the processing that enhances those visual edges starts.
So it’s happening in the retina, this entire thing is in the retina. What happens is if it’s getting a lot of intense stimulation from a group of rods over here, that causes this horizontal cell to inhibit some of the other cells so you do not get as much stimulation from those receptors that are not stimulated as intensely as these over here. So we have a strong stimulation coming via these rods or these receptor cells, and that’s causing inhibition of some of the cells that are not being stimulated as much. This process is called lateral inhibition, and to me it’s a very fascinating concept, showing that strong activity over here can inhibit activity in another area.
That’s all I want to cover in this episode. That’s it for this video. If you have any questions or comments, go ahead and leave them below, and I’ll be happy to take a look at them, and maybe even answer the questions that you might have. That’s all for now, and I’ll see you in the next video.
About The Author Leslie Samuel
Leslie Samuel is the creator of Interactive Biology. He created this site to help Make Biology Fun and has the goal of making this the biggest and best biology resource on the net.
This video is incredibly resourceful. I’m using this to study for my Behavioral Neuroscience Exam. Thank you, and I like your accent.
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This video is incredibly resourceful. I’m using this to study for my Behavioral Neuroscience Exam. Thank you, and I like your accent.
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Thank you so much for posting the video’s on the Special Senses! We have a test on Tuesday and your video’s always make things clear to me.
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I don’t see it either. When I first heard about lateral inhibition I was blown away. This video does not describe it well. I don’t think there is anything wrong with your eyes just this person’s description of the concept.
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I don’t see it either. When I first heard about lateral inhibition I was blown away. This video does not describe it well. I don’t think there is anything wrong with your eyes just this person’s description of the concept.
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5 hours of reading and messing up concepts got clear in 5 minutes!thx!
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5 hours of reading and messing up concepts got clear in 5 minutes!thx!
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5 hours of reading and messing up concepts got clear in 5 minutes!thx!
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Not necessarily. I couldn’t see it at all, at first. The two rectangles are diffferent colors (you do see that part, right?). One is grey (on the right), the other is dark grey (to me, it looks black). When Leslie brought the two rectangles in contact, the thing I can see clearly is that they are, in fact, different colors. One is darker, (left one), one is lighter (right one). The thin strip Leslie is talking about is very small, and’s at the very edge of the border between the two rectangles.
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Not necessarily. I couldn’t see it at all, at first. The two rectangles are diffferent colors (you do see that part, right?). One is grey (on the right), the other is dark grey (to me, it looks black). When Leslie brought the two rectangles in contact, the thing I can see clearly is that they are, in fact, different colors. One is darker, (left one), one is lighter (right one). The thin strip Leslie is talking about is very small, and’s at the very edge of the border between the two rectangles.
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It doesn’t even look like a lighter border — the definition is very faint, and my brain is overriding it by telling me that it is just the two rectangles. This might be the case with you, as well. The border IS very fine — more of a shimmering at the edge, than a real color difference — it’s just a minor detail, one of those blink-it-and-you’ll-miss-it, kind of things.
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It doesn’t even look like a lighter border — the definition is very faint, and my brain is overriding it by telling me that it is just the two rectangles. This might be the case with you, as well. The border IS very fine — more of a shimmering at the edge, than a real color difference — it’s just a minor detail, one of those blink-it-and-you’ll-miss-it, kind of things.
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Comment was too long. Read my comment entitled “Not necessarily” first, then the “It doesn’t…” one.
Best of luck to you!
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Comment was too long. Read my comment entitled “Not necessarily” first, then the “It doesn’t…” one.
Best of luck to you!
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Nice Video, your stuff is helping me while learning for my german oral exam tomorrow. Thanks!
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Nice Video, your stuff is helping me while learning for my german oral exam tomorrow. Thanks!
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cool. it took me a while to see, but i saw!
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cool. it took me a while to see, but i saw!
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cool. it took me a while to see, but i saw!
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photoshopped just kidding
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photoshopped just kidding
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is there a video on population coding? or maybe are you able to quickly just explain it?
Cheers
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is there a video on population coding? or maybe are you able to quickly just explain it?
Cheers
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This was very helpful! Especially the visual aid! Understand it a whole lot better now! XD Thanks!
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… very helpful
thaaaaaaaaaanks
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very helpful !
thaaaaaaaaaaaanks
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Great vid!!!!
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And I can even see the lighter area on my phone lol
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Thank you for that vid
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Thank You! You cleared up what I spent hours trying to figure out in under five minutes!
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Could someone give a link to that community forums? I couldn’t find it on IB site :-/. And I am too a bit confused. Inhibition coming out from more stimulated cells (light color) would result in dark color being perceived as even darker near the edge. I, however, see area around the black figure as somewhat lighter so there has to be extra stimulation going on. However, I guess that the point of the video was to give a general idea how it works (Ie, that it happens in retina – not in brain)
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Videos are great. The voice is very easy to listen to and the content is correct. Unfortunately, I am unable to see the gradient in color once the black and grey box meet. I am unsure of whether or not my monitor is bad or my eyes are bad. Either way, thanks for the content.
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